Air-pump for inflating pneumatic tires



J. M. E. FRANC.'

MR PUMP FOR INFLATING PNEUMATIC TIRES.

APPLICATION FILED Aue.22. 1919.

1,350,92 Patented Aug. 24,1920.

' lllllllllllllllllyllllllzx d d A J dMEFranc 6 .11 gzw W UNITED STATE-1S PATflfl'l QFl Q JOSEPH MARIE ETIENNE BEANS, OE ANDANCETTE, FRANCE.

Specification of Letters Patent.

Patented Aug. 24:, 1920.

Application filed August 22, 1919. Serial No. 319,273.

T 0 all 207mm it may come-71 n Be it known that l, lessen lv'lixnm Eriiaiini: FRANC, a. citizen of the French liepublic, and resident of Andancette, Department of the Drome, in the Republic of France, have invented certain new and use ful improvements in Air-Pumps for lnflat ing Pneumatic Tires, of which the following is a specification.

This invention relates to improvements in airpumps for inflating pneumatic tires and it has for its object to provide an improved pump having one or more cylinders operated by motor and distinguished by the use of cams, the application of controlling springs for the return of the pistons and the system of engagement and disengagement of the apparatus.

in the accompanying drawings with reference to which the invention is described an air pump is shown having three cylinders. In these drawings Figure 1 shows a section of same along the line i;\ of Fig. 2, and

Fig. 2 is a longitudinal sectional elevation showing the cam-shaft, cylinders, pistons,

to, the valve system being shown on one cylinder only.

shown the apparatus consists of three cylinders a cast solid or in parts. In the said cylinders the pistons I) move provided with packing rings 0. The pistons 12 are operated, when ascending in the cylinders cams (Z and when descending they are actuated by spiral springs such as c of a truncated cone shape, the large end bearon the upper insioe or cover of the cylwhile the small one rests on the top the pistons Z).

T he cams (Z are keyed on to their shaft d so as to equalize the pressure thereon. The shaft (Z carrying said cams cl rests on the bearings which form part of the frame of the machine which frame forms at 9 an oil chamber in which the cams plunge. The re sult of this immersion is that the whole apparatus is lubricated by the oil projected by centrifugal force.

In the upper part of the cylinders are screwed on covers it which carry the valves and their springs. The whole arrangement is inclosed by a cap 2' which covers all the heads of the cylinders a and is formed at 7' with the air outlet passage. Such passage may also if desired be arranged at the top inuers,

of the cap, or else at the sides. Two small columns It: hold the cap firmly in its place.

The shaft d which carries the cams (Z is hollow. Another shaft Z which carries on one side the spur wheel n, is capable of slidlng longitudinally in its interior. The said shaft is made either square or round with engaging studs which key the two shafts together against relative rotation and give the driving connection.

As the pump is not to be constantly in gear with the motor, a system of engagement and disengagement is prorided lay moving the inner shaft Z which permits the above working. As represented in Fig. 9 the gear wheel 11' engages the motor gear wheel and its helicoidal teeth such 0 are arranged in such manner that the thrust which always accompanies this kind of cog is always produced in the direction of the apparatus and so that under the influence of such thrust, the wheel n therefore always tends to bear against the end 3) of the outer cam shaft d which shaft. is provided at g with a collar provided for manual movement of such shaft where disconnection of the gears is desired.

Hence, while the pump is working, no artificial maintenance of gear connection is necessary considering that it is the thrust of the helicoidal teeth which stabilizes the starting gear.

For the disengagement, all that is necessary is to displace the gear wheel n by pushing back the inner shaft Z by means of the collar on. During this performance, the sliding inner shaft Z effects the disengagement of the gear w icels and then the pump is at once stopped.

Circumferential apertures (Fig. 1) are provided around each cylinder for the ad mission of air into the cylinders, except in those parts where they are in contact.

In order to facilitate the guiding of the piston and to avoid wear, the cam shaft is out of center relatively to the center of the pistons and the cylinder.

fin oil hole not shown in the drawing, is provided for filling up the oil case 5 For the purpose of reducing the weight, the pistons may be hollow and the cams may be provided with holes theret-hrough and for cooling purposes ribs may be provided at the to 3 of the cylinders and on the back.

What claim is 1. An air pump for inflating pneumatic tires comprising a casing, a plurality of cylinders thereon, valves in said cylinders, pistons slidably mounted therein, a cam shaft, cams on said shaft in operative engagement with the pistons, the said cams being in equal angular relation on the shaft according to the number of cylinders, and spiral springs bearing on the tops of the pistons for keeping them up to the working faces of the cams on the return strokes of the pump, the cam shaft being made hollow and having slidably mounted therein another shaft, a spur wheel secured on such inner shaft and formed to be held in engagement with a cooperating pinion through its tooth formation, whereby the inner shaft may be moved to disengage such spur wheel at will.

2. An air pump for inflating pneumatic tires, comprising a plurality of cylinders opening into a bottom casing, springpressed pistons mounted in the cylinders, a hollow cam shaft mounted in the casing and having a cam foreaeh piston, a cover for each cylinder having a valve controlling the outlet for such cylinder, a cover for all said valves forming an air chamber for all cylinders, and driving means mounted in and longitudinally operable relative to such hollow shaft. I

In testimony whereof I have hereunto signed my name. JOSEPH MARIE ETIENNE FRANC.

\Vitnesses MARIN GAoHoU, lVIARIUS MERMAR. 

